HVAC system qualification and validation
The procedures for HVAC validation are now commonly understood. HVAC system validation is always based on design. Engineers and owners design systems, and validation specialists interpret these designs and reduce this information in the form of protocols. Quality assurance professionals and regulatory authorities review the designs at various stages of development to ensure compliance with GMP regulations and appropriate industry standards (7).
The standard sequence for HVAC system validation is installation (IQ), operational (OQ), and performance qualification (PQ). To ensure regulatory compliance, design review begins when drawings and specifications are approximately 35% complete, but always before long lead-time equipment is ordered from vendors (7). Rarely are serious errors or omissions noted during review of HVAC designs, because design criteria are understood by reputable engineers and engineering companies designing these systems.
In nearly all pharmaceutical facilities, multiple air handlers exist, each designed to support a specific zone within the building. Each zone is exhausted by one or more exhaust fans interlocked with the air-handling unit (AHU), and depending on design, return fans also. IQ and OQ protocol boundaries should be set that encompass one AHU and the interlocked return and exhaust fans only. HVAC zones do not operate in isolation but are influenced and controlled by conditions in adjacent zones. This is an important consideration when confirming room pressurizations and air-flow directions during OQ.